1. Field of the Invention
The invention pertains to a clamping device for removably holding a first machine part that is provided with the conical drilled shank on a second machine part that is provided with a taper bore.
2. Prior Art
A clamping device of this type is known from DE 299 22 642 U1. In this case, several clamping claws are combined into clamping segment grippers within a work spindle that is provided with a taper bore, wherein the front ends of said clamping claws contain oblique clamping surfaces that come in contact with corresponding clamping bevels on an annular groove in the interior of the conical drilled shank. Radially elastic holding grippers with holding tabs that extend parallel to the clamping claws are also arranged in the work spindle. Oblique holding surfaces that correspond to the clamping bevels are arranged on the individual holding tabs, wherein the oblique holding surfaces abut the clamping bevels of the conical drilled shank in the idle position of the holding tabs. Due to the additional holding tabs, the conical drilled shank is also held in position if the clamping claws have not yet come in contact with the clamping bevels or the clamping claws have already been released. In a clamping device of this type, the shape and position of the oblique holding surfaces on the holding tabs need to be exactly adapted to the corresponding clamping bevels of the conical drilled shank. This requires a precise manufacture and an exact installation. In addition, a comparatively high withdrawal force initially needs to be exerted when the conical drilled shank is removed from the work spindle, in order to move the holding tabs that positively engage in the annular groove radially inward in order to release the conical drilled shank. As soon as the oblique holding surfaces of the holding tabs are disengaged from the clamping bevels, the tool is suddenly released such that the holding force abruptly diminishes.